The mystic had already made a name for himself as a spiritual adviser to celebrities and political leaders including Nancy Reagan, Elizabeth Taylor, the Sultan of Brunei and controversial Saudi businessman Adnan Khashoggi.

But Mr Singh was still astonished when Mrs Thatcher agreed to meet the guru, albeit insisting the session would last only ten minutes.

It is claimed Mr Chandraswamy arrived at her Commons office wearing an orange shawl, with a tilak mark on his forehead, beads around his neck and carrying a staff in his right hand.

After introducing himself, he gave Mrs Thatcher five strips of paper and, with Mr Singh’s help as translator, asked her to write a question on each.

She obliged with 'scarcely camouflaged irritation’ and watched as the guru closed his eyes and went into a trance.

When he emerged, he asked Mrs Thatcher to open the paper balls one by one, and correctly told her the question written on each.

“Irritation gave way to subdued curiosity,” Mr Singh recalled. “By the fourth question, I thought, she began to consider Chandraswamy a holy man indeed. Chandraswamy was like a triumphant guru and took off his slippers and sat on the sofa in the lotus position.

“I was appalled but Mrs Thatcher seemed to approve. She asked more questions and, in each case, Chandraswamy’s response overwhelmed her.”

The mystic cut short the meeting when he announced that the sun had set, meaning he was unable to continue.